Numerische Untersuchungen zur Elektromigration auf metallischen Oberflächen

Schimschak, M.

Dissertation / PhD Thesis/Book

Numerische Untersuchungen zur Elektromigration auf metallischen Oberflächen

Schimschak, M.FZJ*

1999
Forschungszentrum, Zentralbibliothek Jülich

Jülich : Forschungszentrum, Zentralbibliothek, Berichte des Forschungszentrums Jülich 3635, (1999) = Essen, Univ., Diss., 1999

Please use a persistent id in citations: http://hdl.handle.net/2128/4432

Report No.: Juel-3635

Abstract: Surface electromigration refers to the directed motion of atoms at solid surfaces and interfaces which is caused by an electric current in the bulk of the material. It is considered a key factor determining the reliability of integrated circuits. Based on this background the influence of electromigration on the stability of metallic surfaces is treated within a continuum theory. The nonlocal coupling between the electric field and the surface evolution leads to a moving boundary value problem which is solved numerically for stripe geometries and for voids inside infinitely or semi-infinitely extended conductors as weIl. Strip es show a scale-dependent drift of surface features and may be unstable in the presence of an anisotropie adatom mobility. The instability leads to the formation of facets which become unstable again due to the onset of coarsening of the surface. In the presence of an isotropie adatom mobility circular voids are linearly stable, but become unstable beyond a finite threshold deformation amplitude which decreases with increasing void radius . If a void is initially elongat ed along the electric field direction it expels small, st able daughter voids, while for elongations perpendicular to the field the void is split horizontally in two. The behavior near threshold is linked to the non-normality of the linear perturbation t heory. Beyond t hat , t he interaction of two voids or one void and a surface is studied as well as the effect of an anisotropie adatom mobility

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